With the development of technologies, organic electroluminescent displays (OLEDs) have gradually become the mainstream in the display field by virtue of excellent performances, such as low power consumption, high color saturation, wide view angle, thin thickness, and flexibility. At present, the full color display of OLEDs is generally implemented by using red (R), green (G) and blue (B) sub-pixels that emit light independently, or by combining a white light OLED with a color filter, and so on. When RGB sub-pixels in the OLEDs are arranged in juxtaposition, light-emitting layers are mainly prepared by a fine metal mask (FMM) technology in nowadays. However, the FMM technology is faced with many difficulties, such as manufacture, washing and deposition of the mask, and many problems, such as alignment and expansion of the FMM during the process. As a result, the color mixing of a display panel is severe, the product yield is low, and the manufacture cost is expensive. Besides, the accuracy control of the FMM is very difficult, which makes it harder to achieve OLEDs with a high resolution. When OLEDs are implemented by combining a white light OLED with a color filter, the white light is absorbed by the color filter. This results in quite little effective light output, and thus a very high power consumption of the product as a whole.
According to the different numbers of light-emitting units, OLEDs can be divided into one-unit OLEDs and stacked OLEDs. Specifically, as shown in FIG. 1, when a stacked OLED device is used, a plurality of light-emitting units 03 connected in series are provided between a cathode 01 and an anode 02 (three light-emitting units connected in series are shown in FIG. 1). With the same brightness, as compared with a conventional one-unit OLED device, the stacked OLED device has a longer service life but less effective light output, which leads to a high power consumption. Taking FIG. 1 as an example, for R pixels: about ⅙ of the light can be utilized; for G pixels: about ⅙ of the light can be utilized; for B pixels: about ⅔ of the light can be utilized; and for W pixels: about 100% of the light can be utilized. Thereby, as can be seen, the R and G pixels have higher power consumption and less light output than the rest of pixels.
Therefore, how to use a new structure design to reduce the product power consumption and improve the resolution is an urgent technical problem for those skilled in the art.